Vacuum-type circuit interrupter with grounded metallic housing and removable operating mechanism tray

ABSTRACT

A circuit interrupter of the vacuum type is provided, of the inline type, having a central grounded housing and oppositelyextending hollow bushing structures, through which extends an elongated conducting operating rod actuating the movable contact of a vacuum-type circuit-interrupter unit disposed in one of the hollow bushing structures. An insulating main operating lever provides additional insulation between the grounded operating mechanism structure and the live elongated conducting operating rod, which effects the movement of the movable contact within the vacuum-type circuit interrupter.

Unite States atent n91 Harvey VACUUM-TYPE CIRCUIT INTERRUPTER WITH GROUNDED METALLIC HOUSING AND REMOVABLE OPERATING MECHANISM TRAY [75] Inventor:

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Nov. 10, 1970 [21] Appl. No.: 88,287

Related US. Application Data [62] Division of Ser. No. 770,490, Oct. 25, 1968, Pat. No.

Ian J. Harvey, Bloomington, Ind.

[52] US. Cl.......200/l44 B, 200/153 SC, 200/153 R, 174/127 [51] Int. Cl. ..I-I01h 3/54, l-l0lh 33/66 [58] Field of Search ..200/146 AA, 144 B,

200/163, 153 SC, 148 R, 153 R, 172A, 50 AA; 317/101 CB; 174/127 [5 6] References Cited UNITED STATES PATENTS 3,209,101 9/1965 Peek et al ..200/144 B X STATIC CONTROL 5b [451 Apr. 10, 1973 3,114,815 12/1963 Easley etal ..200/148 A 3,096,210 7/1963 Boonstra ..174/127 UX 3,352,988 11/1967 Wachta et al ..200/144 B 3,291,948 12/1966 Telford ..200/148 R X Primary ExaminerRobert K. Schaefer Assistant Examiner-Robert A. Vanderhye Att0rneyA. T. Stratton, Clement L. McHale and Willard R. Crout [5 7 ABSTRACT A circuit interrupter of the vacuum type is provided, of the in-line type, having a central grounded housing and oppositely-extending hollow bushing structures, through which extends an elongated conducting operating rod actuating the movable contact of a vacuum-type circuit-interrupter unit disposed in one of the hollow bushing structures.

An insulating main operating lever provides additional .insulation between the grounded operating mechanism structure and the live elongated conducting operating rod, which effects the movement of the movable contact within the vacuum-type circuit interrupter.

8 Claims, 20 Drawing Figures OPEN 2 59 MANUEL 1 CLOSING PATENIE APR 1 0197s SHEET 1 [1F 7 LOAD CLOSED COUNTE R OPEN POSITION PATENTEU APR 1 01m SHEET 4 UF 7 1 vm. l

ZOELmOm owm o PATENTEDAFR 1 (H973 SHEET 6 BF 7 mOkQOEE Pmmntmmw 3,727. 019

sum 7 OF 7 INS'I'. TRIPS o 0 0 o o INTEGRATOR TRIPS T0 1.0.

oooo o F|G.|5.

INST. RECL.

o o o 0 o FIG.|6.

INTEGRATOR v l7 r0 ,85 FIG.

.5 Q1 E R 85 I i U INST. TRIPS 2 STATIC CONTROL TIMING 00 TRIP CLOSE TRANSFORMER CIRCUIT AMPLIFIER COIL 7 WW? I 63 #:2- C APACITOR CURRENT TRANSFORMER RECLOSING v SECONDARY BRIDGE TIMRER RECTIFIER A RESET 1 I INTEGR TOR TIMER 84 OPERATIONS A c -T0 LOCKOUT FIG.I9. RECLOSER VACUUM-TYPE CIRCUIT INTERRUPTER WITH GROUNDED METALLIC HOUSING AND REMOVABLE OPERATING MECHANISM TRAY This application is a division Patent application of U.S. Patent application filed Oct. 25, 1968, Ser. No. 770,490, by Ian J. Harvey entitled Circuit-interrupter Construction and Operating Mechanism Thereof or With Particular Application to Single-Phase Reclosers, Pat. No. 3,564,465, and assigned to the assignee of the present application.

CROSS-REFERENCE TO RELATED APPLICATIONS Reference may be made to U.S. Pat. No. 3,114,815, issued Dec. 17, 1963', to 'C. J. Easley et al., and assigned to the assignee of the instant application, for a somewhat similar type of sulfur-hexafluoride (SP type circuit interrupter, in which a generally in-line construction of the conducting components is employed. Applicant does not know of any other patented structures pertinent to the instant invention.

BACKGROUND OF THE INVENTION In the field of single-phase distribution and power class protective equipment, oil-filled reclosers have so far been dominant in use. Oil-filled equipment is both heavy and requires regular servicing for it to retain its original efficiency. Also, the fire and explosion hazard is always present in the event of a malfunction of the equipment.

Recent technology has introduced a vacuum-type interrupter element in a size suitable for single-phase equipment. This type of interrupter has a far superior interruption life, and eliminates many of the problems associated with oil-filled equipment. The use of a vacuum interrupter does, however, impose special requirements upon the operating mechanism. First of all, it is desirable that the interrupter must always open and close quickly, preferably with a snap action, during both manual and automatic operations. Secondly, it is desirable that the operating mechanism should prevent contact bounce within the interrupter element, and must apply a high predetermined contact pressure when the butt contacts, interiorly of the evacuated envelope of the circuitinterruptcr unit, are in the closedcircuit position.

One of the many advantages to be obtained from the use of vacuum interrupters in reclosers and switches is the elimination of the hazard to persons and property from oil, fire or explosion, which can result from the malfunction of present oil-filled circuit-interrupting equipment. However, because of the good dielectric properties of oil, its removal from the dielectric system does introduce additional problems.

One of the features of the present invention is the use of a load-current-carrying member as the actualv operating rod for an electric circuit interrupter. Such an arrangement is preferably used in order to optimize the size of the equipment, while still retaining the required electrical characteristics. Radio interference arises from a breakdown in the dielectric between electrical conductors at differing potentials. The threshold of electrical flashover is also lowered when localized areas of high electrical stress occur in a dielectric field. Spacing of conductors in a recloser or switch design is, therefore, of the utmost importance.

The present invention has, as a further aspect, the utilization of a combined conductor-operating rod, which serves to place the elongated conductor in the optimum position, thus minimizing the electro-static field stresses. In more detail, the present invention is, in part, particularly concerned with devices using an inline" bushing arrangement with the interrupter contained in one bushing.

In U.S. Pat. No. 3,114,815, issued Dec. 17, 1963, C. J. Easley et al., and assigned to the assignee of the instant application, there is illustrated a sulfur-hexafluoride (SF puffer-type circuit interrupter in which a grounded centralhousing is provided with oppositelyextending hollow bushing structures, within one of which is disposed a puffer-type, or piston-type circuitinterrupting unit. It is a purpose of the present invention to improve upon the aforesaid type of in-line circuit interrupter, rendering it capable of reclosing operations and improving the associated interrupting and mechanism structure.

SUMMARY OF THE INVENTION In accordance with one particular aspect of the present invention, there is provided a grounded-centrally-disposed operating mechanism housing having oppositely-extending hollow bushing structures, within one of which is provided a vacuum-type interrupter element. A longitudinally-extending operating and contact rod extends through both hollow bushings, and has an operating lever connection with a grounded operating mechanism disposed adjacent the lower end of the central grounded housing.

Accordingly, it is a general object of the present invention to provide an improved circuit-interrupting structure of the vacuum type reducing the electrical stresses, and consequently the hazard of radio interference, by an improved location and disposition of the several conducting parts at differing potentials. Moreover, it is a distinct objective of the present invention to reduce the size of the entire circuit-interrupting structure as much as possible, without generating radio interference, by the employment of insulation and a centralized position, which is conducive to a minimum spacing.

Another object of the present invention is the provision of an insulating operating lever providing the spacing desired between a grounded operating mechanism and the longitudinally-extending operating and contact rod of a vacuum-type circuit interrupter.

It is an additional purpose of the present invention to provide a vacuum-type circuit interrupter of the reclosing type, particularly adaptable for single-phase distribution circuits, of relatively light weight and of simplified construction, which may be utilized in large quantites throughout distrubition systems. I

Another object is to provide an improved single-style of recloser which may be used at any location on the distribution circuit where the full-load current does not exceed the maximum continuous rating. Also by a simple adjustment of a tap setting, different minimum current pickups may be selected depending upon the operating requirements. A simple static device may be used to achieve this end.

Another object is to provide an improved circuit reclosure in which a grounded mechanism housing and the bushings, together with the interrupter element,

may be removed from the tray supporting the operating mechanism, integrator, time-current device, counter, and position indicator so that ready accessibility for maintenance may be achieved.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevation view of a single-phase vacuum-type recloser embodying the principles of the present invention, and shown mounted upon an upstanding wooden support pole;

FIG. 2 is a plan sectional view taken substantially along the line II-II of FIG. 1 looking in the direction of the arrows, and indicating a top plan view of the circuit interrupting structure of FIG. 1;

FIG. 3 is a longitudinal enlarged sectional view taken through the circuit-interrupting housing and bushing structures, with the contact structure being illustrated in the closed-circuit position, and the mechanism and integrator structure being eliminated for purposes of clarity, the view being taken along the line III-III of FIG. 4;

FIG. 4 is a top plan view of the housing and bushing structure of FIG. 3 taken along the line IV--IV of FIG.

FIG. 5 is an enlarged side elevational view of the quick-opening and quick-closing mechanism structure utilized in the improved re'closer-type interrupter of the present invention, the mechanism parts being indicated in the open tripped position;

FIG. 6'is an end elevational view of the mechanism structure of FIG. 5 taken substantially along the line VI-VI of FIG. '5, looking in the direction of the arrows; FIG.-7 is a view generally similar to that of FIG. 5, but illustrating the position of the several component parts of the operating mechanism in the closed-circuit position of the interrupter;

FIG. 8 is a fragmentary plan sectional view taken substantially along the line VIII- VIII of FIG. 5;

FIG. 9 is a side elevational view of the mechanism structure in relation to the tripping device and integrator structure;

FIG. 10 is a top plan view of the mechanism structure of'FIG. 9 taken along the line X-X thereof;

FIG. 11 is a side elevational view of the mechanism structure of FIGS. 9 and 10, but viewed from the side looking in the direction of he arrow XI-XI of FIG. 10;

FIG. 12 is a vertical section detailed view of the bifurcated insulating main operating lever of the mechanism taken along the line XII-XII of FIG. 14;

FIG'. 13 is an end elevational view of the bifurcated insulating main operating lever of FIG. 12;

FIG. 14 is a top plan view of the same main operating lever;

FIG. 15 is a top plan view of the integrator structure of FIG. 16;

FIG. 16 is a side elevational view of the integrator FIG. 18 is an end elevational view of the reclosure of FIG. 3 taken along the line XVIII-XVIII of FIG. 3 looking in the direction of the arrows;

FIG. 19 is a block diagrammatic view of the static control circuit for the reclosure; and

FIG. 20 is a fragmentary inverted plan view of the mechanism housing looking upwardly from the ground to observe the position indicator and counter openings provided in the bottom of the housing.

DESCRIPTION OF THE PREFERRED EMBODIMENT orly of a hollow insulating tubular bushing structure 4,

through the grounded mechanism housing 5, and through an interrupting structure 6 disposed interiorly within the oppositely-extending hollow bushing structure 7 to the other line terminal 8, and thence to the other line L I It will be observed that there is provided a channelshaped vertically-extending metallic support plate 9, transversely of which is secured, as by welding at 10, a tubular metallic supporting structure 11, to the lower side 11a of which is welded a supporting metal plate 12. The supporting metallic plate has four mounting holes provided therethrough, through which extend mounting bolts 13, which are secured to the upper metallic cover structure 50 of the single-phase reclosing-type circuit interrupter 1.

The upright wooden supporting pole 16 may, for example, extend upwardly for a distance say, for example, of 25 feet, and the circuit L L is controlling a dis tribution circuit (not shown) as well understood by those skilled in the art.

FIGS. 3 and 4 generally illustrate the interior of the circuit interrupter 1 with the details of the operating mechanism 2 being omitted for purposes of clarity. Generally, it will be observed that there is provided a pair of insulating hollow bushing structures, 4, 7, which are clamped, as by clamps 4a, 7a, to the opposite ends 5b, 5c of a generally rectangularly-shaped grounded metal mechanism housing 5. Extending longitudinally through the interior of the hollow bushing structures 4, 7, and also, of course, interiorly through the grounded mechanism housing 5, is a reciprocally-movable conducting operating rod 18 having a movable sliding contact 19 disposed at its left-hand end, which makes contacting engagement with a plurality of circumferentially-disposed contact fingers 20, biased radially inwardly by a tension,'or garter spring 21. The righthand end of the longitudinally-movable conducting operating rod structure 18 is attached at 22 to the movable contact 23 of a vacuum-type circuit interrupter element 6, which is, as shown in FIG. 3, disposed interiorly of the right-hand hollow bushing structure 7. The stationary contact 25 of the vacuum-type circuitinterrupter element 6 is fixedly connected to the terminal structure 8, which is clamped within an aperture 26 provided at the right-hand extremity of the righthand hollow bushing structure 7.

It will be observed that the inner end of the bushing structure 4 extends inwardly into the grounded housing structure 5 and improves the electrical insulation and dielectric conditions adjacent the hot" or live conducting contact rod 18. The conducting operating rod 18 is insulated by a tube 18a of suitable insulating material, the two pieces being solidly mechanically connected together. The rod assembly 18 is positioned along the axis of the two hollow bushings 4, 7, and this achieves optimum spacing from the grounded metal housing 5 thus reducing electrical stress to a minimum. In this way, the radio interference, normally associated with high-voltage conductors, is eliminated over the range up to maximum design voltage of the device. In other words, by the provision of the insulating sleeve portion 4b, extending inwardly from the bushing structure 4, an increase in the striking distance to ground is achieved.

A current transformer CTl (FIG. 3) is utilized, surrounding the inwardly-extending sleeve portion 4b and clamped into position, as at 29. This, of course, permits a measurement of the amperage value of current passing through the circuit interrupter 1 and senses any fault or overload conditions.

Also, it will be noted that the right-hand hollow bushing structure 7 also has an inwardly-extending sleeve portion 7b surrounding the reciprocally and longitudinally-movable conducting operating contact rod 18.

To effect the reciprocal motion of the conducting operating rod 18, and consequently to effect a corresponding opening and closing movement of the movable contact 23 disposed interiorly within the vacuum-type circuit-interrupting element 6, there is provided a grounded operating mechanism, generally designated by the reference numeral 2, and comprising a grounded portion, which is insulated from the live, or hot conductor rod 18 by the intermediary of a bifurcated insulating main operating lever 31, more clearly shown in FIGS. 12-14 of the drawings. The main insulating operating lever 31 may, for example, be made of a suitable arc-resisting insulating material, such as that set forth in U.S. Pat. No. 2,768,264, issued Oct. 23, 1956, and assigned to the Rostone Corporation of Lafayette, Ind. The conducting operating rod 18 carries its own insulating sleeve 18a, as mentioned hereinbefore.

The operating lever 31 is non-conducting simply to stand off the high-voltage conductor assembly 18 from the grounded mechanism 2. If it were conducting, it would be at ground potential directly adjacent to the high-voltage conductor 18, and high electrical stresses would result. This would give rise to increased radio interference and would reduce the value of voltage impulse withstand.

With further reference to FIG. 3, it will be observed that the vacuum-type circuit-interrupting element 6 is seats against a movable sleeve 35, which is secured to the furcations 31a of the bifurcated main insulating operating lever 31, as heretofore described.

With reference to FIGS. 5-7 of the drawings, it will be apparent that the main operating lever 31 is pivotally mounted upon a stationary pivot pin 36. The right-hand end 31b of the main operating lever 31 is pivotally connected, as at 38, to a closing toggle linkage 40 comprising a pair of toggle links 40a, 40b, pivotally connected by a knee pin 40c.

The toggle link 40b has an L-shaped configuration for convenience of alignment with a knee-pin located at 40c and also providing a pivot connection at 40d to a main closing link hereinafter described. The lower end of the toggle link 40b is pivotally connected, as at 42, to a rotatably mounted latching lever, generally designated by the reference numeral 43, and pivotally mounted on a stationary pivot pin 44. It will be observed that in the reset position of the latch lever 43 that a tripping latch 46 latches a roller 43a pivotally mounted between the spaced side-plate portions 43b, 43c of the latching lever, the latter assuming the form of a channel-shaped member.

An opening spring means 48, in this particular instance comprising a pair of tension springs 49, 50, are pivotally mounted to the pivot pin 38, and also to a stationary pivot pin 51 mounted through the side walls 2a, 2b of the mechanism frame, as more clearly illustrated in FIG. 6 of the drawings.

A pair of rollers 52 are pivotally mounted on the knee pin 40c and bear against a fixed stop 54. A main driving link 56 is pivotally mounted to a bellcrankshaped actuating lever 57, as at the pivot pin 58, and additionally pivotally connected to the leg portion 40e of toggle link 40b at the pivot connection 40d.

A rotatably-mounted cam 60 is preferably motordriven, and bears against a driving roller 61 extending between the two bellcrank-shaped actuating levers 57a, 57b, which are pivotally mounted on a stationary pivot pin 62. Thus, clockwise rotation of the cam by a motordriven mechanism 63, forexample, will effect a raising of the roller bearing 61, which, in turn, will effect a clockwise rotation of the pair of actuating bellcrank levers 57a, 57b to thereby tension a closing spring 65, in this'particular instance comprising a heavy tension spring mounted at one end to a fixed stop 66, and at the other end to a moving pivot 67 connected between the bellcrank levers 57a, 57b.

I have provided a construction in which the toggle linkage 40 is held under center against stop 54 by the closing spring 65 in an attempt to minimize the travel and energy requirements imposed upon the mechanism. In this way, the size of the closing motor and size and stressing of the closing spring can be kept to a minimum.

To drive the closing toggle over center would provide very little extra motion to the operating lever 31, and would require a significant increase in the energy input required. The additional motion required would also tend to increase the total operating time of the mechanism.

TRAY ASSEMBLY 27 The construction of the housing and mechanism assembly were designed specifically for ease of assembly and maintenance. All control and operating means are mounted on a simple tray assembly. Once the leads from the current transformer have been disconnected and the bolts joining thesleeve 3-5 to operating lever 31 have been removed, then the housing 5 may be unbolted from the tray assembly 27 and removed completely. Access to all operating portions of the mechanism 2 is then immediately available. Reference may be made to FIG. in this connection.

CLOSING OPERATIONS During the closing operation, energization of the motor 63 will effect clockwise closing rotation of the cam 60. This, in turn, will cause a raising of the roller bearing 61 and, consequently, a clockwise rotation of the actuating-bellcrank arms 57a, 57b. This will not only tension the relatively heavy closing spring 65, but, additionally, will reset the latch lever 43 so that it again will be latched under the tripping lever 46, as more clearly illustrated in FIG. 7. When the roller bearing 6 I slides off of the abrupt cam surface 60a, as to 60b, this will permit a rapid counterclockwise rotative movement of the actuating levers 57a, 57b, and thereby permit the heavy closing spring 65 to effect a quick straightening of the closing toggle 40 to thereby effect a counterclockwise rotative closing motion of the bifurcated insulating main operating lever 31. This will, through the contact compression spring 33, effect a closing of the contact structure 23, 25 within the vacuum-interrupting unit 6, and the additional compression of the contact spring 33, as effected by the sliding sleeve 35, will provide the requisite contact pressure in the closed position of the separable contact structure. I

For certain applications where it may not be desirable to energize the closing motor 63, a manually-operable crank means 69, having a lost-motion connection with the hub of toggle link 71 (FIG. 8), may be utilized to effect a straightening of the closing toggle linkage 40, comprising a pairof links 70, 71 pivotally connected. at a knee pin 72. This will cause a similar tensioning of the closing spring 65 and a similar closing operation of the interrupter 6 with a snap action.

To prevent the mechanism parts from going solid, an overtravel compression spring 73 is provided between a pin 74 riding in a slot 75 provided in the main driving link 56. This will provide a desirable overtravel, as caused by an excessive clockwise rotation of the actuating arms 57a, 57b, even though the other component parts of the mechanism 2 contactingly engage fixed stops. Thus, a certain flexibility at the end of the closing operation is achieved by the compression spring 73.

The mechanism 2 includes an interference means 88 for preventing a manual closing operation of the mechanism 2, when the latter has already been closed, say by the motor 63. In more detail, a pivotallymountedlatch 88 is pivotally mounted upon a stationary pin 88a, and has the latched portion 88b thereof engaging a pin 90, which extends through the lower ends of the pair of spaced bellcrank-shaped actuating levers 57a, 57b. Thus, when the operating mechanism 2 is in the closed position, as illustrated in FIG. 7, the latch 88 will prevent straightening of the closing toggle, comprising the toggle links 70, 71, by the manual means 69.

The manual closing means comprises a manually operable lever 69 extending through the side wall of the mechanism housing 5 and having an externally disposed hook portion 69a, which may be engaged by a suitable switch stick (not shown), as well known by those skilled in the art. The manual closing means 69 has a pin 69b, which engages a slot 71a extending transversely through the shaft portion 71b to which the lower toggle link 71 is fixedly secured. Thus, counter clockwise rotation of the manual closing lever 69a, as

TRIPPING OPERATION To effect a tripping operation, the clockwise rotation of the tripping latch 46 is provided either manually, or

automatically in response to the value of current passing through the interrupter, as sensed by the current transformer CTl. As shown more clearly in FIGS. 10 and 11 of the drawings, a solenoid 77-is employed to raise a plunger 78 and thereby effect rotation of a tripping arm 79 (FIG. 11), which, in turn, will effect clockwise rotation of the tripping lever 46 to thereby release the latch lever 43, and thereby permit collapse of the main closing toggle 40. This will effect an opening operation. Also, manual tripping may be achieved by a manual trip lever 81 which is more clearly shown in FIG. 10, and causes, through a linkage 83, similar rotative movement of the tripping latch 46. When manual tripping is effected a means is provided whereby the motor circuit is opened prior to the tripping operation. This prevents automatic reclosing of the device and removes the necessity of running through a complete normal operating sequence before lockout is achieved. r

The switch used to open the motor circuit is automatically reset when the recloser is returned to the closed position.

INTEGRATOR ASSEMBLY effect an energization of the closing motor 63 to effect I through the linkage successive closing operations. Finally, a lockout condition is achieved upon a predetermined number of openings and closing operations, all as counted by the integrator assembly 84. Since the integrator assembly 84 is rather conventional,

and operates in a manner similar to those of the prior art, it has not been described in detail.

STATIC CONTROL The static control of the SPV recloser provides the time v. current characteristic and trip signal only.

The primary of the current-to-voltage transformer is connected to the bushing current transformer CTl. The secondary voltage is fed through a full wave bridge to the trip timing circuit. The voltage applied to the trip timing circuit is proportional to the magnitude of the fault current passing through the reclosure.

The trip timing circuit feeds a signal to a DC. amplifier, which is, in turn, connected to the trip circuit.

The trip circuit consists of a silicon control rectifier to which a capacitor is connected. The capacitor is kept charged by rectified lVAC fed through dropping resistors. Upon receiving a signal of the proper magnitude from the DC. amplifier, the SCR allows the capacitor to discharge through the trip coil 101, thus tripping the recloser.

Each static control has included as standard equipment two distinct time curves. Usually one is fact or instantaneous, and the other an inverse time delay. (Replacement plug in printed circuit boards are available with a variety of curves.) Switching from fast trip to time delay is accomplished by a switch mounted external to the static control on the integrator. The curves remain consistent within an accuracy of plus or minus 5 percent throughout the temperature range C to +70C.

The current to voltage transformer is set up with a number of different taps. Thereby the minimum current required to initiate tripping of the recloser can be selected by proper positioning of the tap screw in the tap-type terminal block. 1

The static control may be as illustrated in a co-pending patent application of Francis T. Thompson, Ser. No. 708,898, filed Feb. 28, 1968, and assigned to the same assignee as this application. Additional background material is presented in U.S. Pat. application filed Aug. 5, 1968, Ser. No. 757,186 by Nathaniel D. Tenenbaum, and likewise assigned to the assignee of the present application.

From the foregoing description it will be apparent that there has been provided a novel in-line circuit interrupter construction I particularly adapted for reclosing operations, and of compact size and dimenslons.

By the use of tubular bushings 4, 7 having extending sleeve portions 4b, 7b, a diminution of the electrical stress about the conducting operating rod 18 has been achieved to minimize the chance of radio interference.

For ease of maintenance, by the removal of the bolts 105 (FIG. 3) and mtg. bolts 107, the housing 5 together with the bushings 4, 7 may be removed from the tray 111 supporting the mechanism 2, integrator, counter and position indicator, and thereby ready visible access to the mechanism obtained.

The circuit recloser 1 is completely self-contained, and does not need any control wiring extending down to ground potential. A step-down transformer CT2 has its primary connections between the source terminal and the grounded case 5. The secondary of the stepdown transformer CT2 provides energy for the motor circuit to energize the motor for automatic closing operations of the interrupter.

The use of the static control with adjustable tap settings provides a desirable arrangement in which the recloser 1 may be removed to a different distribution circuit, and by a mere resetting the tap screw in connection with the static control device may be applied for different current ratings in different distribution circuits. Previously, this involved a different series coil for prior-art types of reclosers. In the present construction, however, as mentioned, only a different setting of the tap terminal is needed.

Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

I claim as my invention:

1. In combination, an in-line circuit interrupter in cluding a pair of hollow insulating bushings and an intervening metallic mechanism housing, a combined conductor and operating rod extending axially centrally through said hollow insulating bushings, an operating mechanism having an operating member removably connected to said operating rod and secured to a tray, said tray closing one side of the mechanism housing and removable therefrom for maintenance purposes.

2. The combination of claim 1, wherein the operating member is of insulating material.

3. A circuit breaker including a metallic mechanism housing, a pair of oppositely-extending tubular bushings extending into said metallic mechanism housing, an interrupting unit disposed within one bushing, line-terminal means at the opposite extremities of the two bushings, a longitudinally-movable combined operating-rod and conductor operable generally centrally of said bushings, and the operating mechanism being secured to a tray removably mounted to one side of the metallic mechanism housing.

4. A circuit breaker including a grounded metallic mechanism housing, a pair of oppositely-extending tubular bushings extending into said metallic grounded mechanism housing, a vacuum-interrupter unit disposed within one bushing, line-terminal means at the opposite extremities of the two bushings, said vacuuminterrupter unit having a fixed contact at one end supported by one of the terminal means, and a unitary longitudinally-movable combined operating rod and conductor operable generally centrally of said bushings.

5. The combination of claim 4, wherein a current transformer encircles the inward protruding sleeve portion of one bushing.

6. The combination of claim 4, wherein an operating mechanism is disposed adjacent the lower part of the metallic mechanism housing, and a bifurcating rotatable main operating lever mechanically interconnects the operating mechanism with the longitudinally-movable conducting operating and contact rod.

7. The combination of claim 4, wherein a sleeve and contact-compression spring encircles the movable operating and contact rod.

8. The combination of claim 43, wherein the conducting operating rod has an insulating sleeve thereabout to improve the electrical field gradient. 

1. In combination, an ''''in-line'''' circuit interrupter including a pair of hollow insulating bushings and an intervening metallic mecHanism housing, a combined conductor and operating rod extending axially centrally through said hollow insulating bushings, an operating mechanism having an operating member removably connected to said operating rod and secured to a tray, said tray closing one side of the mechanism housing and removable therefrom for maintenance purposes.
 2. The combination of claim 1, wherein the operating member is of insulating material.
 3. A circuit breaker including a metallic mechanism housing, a pair of oppositely-extending tubular bushings extending into said metallic mechanism housing, an interrupting unit disposed within one bushing, line-terminal means at the opposite extremities of the two bushings, a longitudinally-movable combined operating-rod and conductor operable generally centrally of said bushings, and the operating mechanism being secured to a tray removably mounted to one side of the metallic mechanism housing.
 4. A circuit breaker including a grounded metallic mechanism housing, a pair of oppositely-extending tubular bushings extending into said metallic grounded mechanism housing, a vacuum-interrupter unit disposed within one bushing, line-terminal means at the opposite extremities of the two bushings, said vacuum-interrupter unit having a fixed contact at one end supported by one of the terminal means, and a unitary longitudinally-movable combined operating rod and conductor operable generally centrally of said bushings.
 5. The combination of claim 4, wherein a current transformer encircles the inward protruding sleeve portion of one bushing.
 6. The combination of claim 4, wherein an operating mechanism is disposed adjacent the lower part of the metallic mechanism housing, and a bifurcating rotatable main operating lever mechanically interconnects the operating mechanism with the longitudinally-movable conducting operating and contact rod.
 7. The combination of claim 4, wherein a sleeve and contact-compression spring encircles the movable operating and contact rod.
 8. The combination of claim 4, wherein the conducting operating rod has an insulating sleeve thereabout to improve the electrical field gradient. 